Signal To Interference Plus Noise Ratio Gain Research Articles

UE Blocking Probability Model for Planning 5G Guaranteed Bit Rate (GBR) RAN Slices

Modeling the probability of blocking User Equipment (UE) sessions is key for planning in advance the amount of radio resources required by a Guaranteed Bit Rate (GBR) slice. This task is challenging since the amount of these resources depends on factors such as the channel quality of each UE, the packet scheduler discipline, and the GBR requirements. Under this context, we propose an analytical model to evaluate the UE blocking probability for a GBR slice. A key aspect of the proposed model is considering as input the distribution of the average Signal-to-Interference-plus-Noise Ratio (SINR) experienced by the UE, therefore allowing to capture the radio conditions in the cell. Our model builds a multi-dimensional Erlang-B system which meets the reversibility property. This involves our model is insensitive to the holding time distribution for the UE sessions. The reversibility property also involves the state transition probabilities have product form, so that the computational complexity of our model is low. Furthermore, the proposed model captures the SINR gain provided when the base station implements a channel-aware packet scheduler to allocate radio resources to the UE sessions. We validate the proposed model, demonstrating an estimation error for the UE blocking probability below 1.5%.

Faster-Than-Nyquist Asynchronous NOMA Outperforms Synchronous NOMA

Faster-than-Nyquist (FTN) signaling aided non-orthogonal multiple access (NOMA) is conceived and its achievable rate is quantified in the presence of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">random</i> link delays of the different users. We reveal that exploiting the link delays may potentially lead to a signal-to-interference-plus-noise ratio (SINR) gain, while transmitting the data symbols at FTN rates has the potential of increasing the degree-of-freedom (DoF). We then unveil the fundamental trade-off between the SINR and DoF. In particular, at a sufficiently high symbol rate, the SINR gain vanishes while the DoF gain achieves its maximum, where the achievable rate is almost <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$(1+\beta)$ </tex-math></inline-formula> times higher than that of the conventional synchronous NOMA transmission in the high signal-to-noise ratio (SNR) regime, with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> being the roll-off factor of the signaling pulse. Our simulation results verify our analysis and demonstrate considerable rate improvements over the conventional power-domain NOMA scheme.

Intelligent Reflecting Surface-Assisted mmWave Communication With Lens Antenna Array

In millimeter wave (mmWave) communication, lens antenna array has been considered as a potential technique to combat the severe path loss. However, blockage effect still exists. To address this issue, we design an intelligent reflecting surface (IRS) assisted wideband mmWave communication system with lens antenna array with limited radio frequency (RF) chains. This is the first attempt to design a mmWave communication system with the integration of IRS and lens antenna array. The designed system can realize high robust, low-complexity and cost-effective mmWave communication. To achieve desired performance, we first derive the signal-to-interference-plus-noise ratio (SINR) expression with the intersymbol interference, then we formulate a SINR maximization problem, by jointly considering the beamforming vector at base station with limited RF chains and reflection coefficient matrices at IRS with discrete phase levels. This problem is intractable and non-convex. To solve it, we optimize the reflection coefficient matrices by quadratic transformation with low-complexity closed-form expression, and the beamforming vector is handled by sparse beamforming optimization, where the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$l_{0}$ </tex-math></inline-formula> norm is approximated by the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$l_{1}$ </tex-math></inline-formula> norm. Finally, simulation results demonstrate the advantages of our proposed algorithm compared with benchmark schemes, e.g., 5 dB SINR gain can be achieved compared with existing algorithm.

Effective SINR for MIMO System with Decorrelation Based Receive Transformation Under Multi-user Interference

We study the effective signal to interference-plus-noise ratio (SINR) of the MIMO detector (or decoder) for the MIMO system with decorrelation based receive transformation (MIMO-DRT), in which the decorrelation based transformation is employed on the received signal of the MIMO receiver. By performing eigendecomposition on the inverse of the covariance matrix for interference plus noise, we express the effective SINR of MIMO-DRT in terms of the eigenvalues of the covariance matrix for interference plus noise and derive the SINR gain (relative to the MIMO system without receive transformation) provided by MIMO-DRT. We prove that the SINR gain provided by MIMO-DRT is larger than or equal to one. Furthermore, we show by both the analytical results and the simulation results that the SINR gain provided by MIMO-DRT increases with the interference to noise ratio and converges to one as the number of cochannel users gets large.

Radio Resource Management Scheme for Relieving Interference to MUEs in Relay-Based Cellular Networks

Relay nodes (RNs) have been recently introduced as a cost-effective solution to achieve ubiquitous high data rates in cellular networks. By providing a two-hop link between evolved nodeB (eNB) and user equipment (UE), RNs can improve the UE's signal-to-interference-plus-noise ratio (SINR) and throughput. A typical relay-based cellular network is comprised of macro UEs (MUEs) that are served directly by eNB and relay UEs (RUEs) that are served via RNs. The performance of the entire network is degraded if the interference between RNs and MUEs is not carefully managed. In this paper, we propose a radio resource management scheme that effectively exploits the advantages of RNs without causing severe interference to MUEs, which yields a better overall network and cell-edge user throughput. To improve channel quality of MUEs located nearby RNs, the proposed scheme determines a specific set of subchannels to be used by each RN. Second, the proposed scheme assigns subchannels to UEs and RNs considering channel quality, average UE data rate, and the number of required subchannels at RNs. For resource allocation, we formulate a binary integer linear programming (BILP) problem and propose a novel heuristic algorithm to reduce its computational complexity. Our simulation results show that the heuristic algorithm achieves similar performance with the BILP. In addition, we discuss a detailed procedure for control signal exchange and data transmission and analyze the lower bound of SINR gain of MUEs obtained from the proposed scheme. It has been shown that the proposed scheme improves the overall network throughput and the cell-edge user throughput compared with existing schemes.

Cochannel interference mitigation using whitening receiver designs in bandlimited microcellular wireless systems

The problem of cochannel interference (CCI) suppression using a noise-plus-interference whitening matched filter (WMF) is addressed. Binary phase-shift keying modulated transmission over a Nakagami-m fading channel is considered in a bandlimited microcellular wireless system. It is shown that the signal-to-interference-plus-noise ratio (SINR) of the WMF can not exceed that of the conventional matched filter (CMF) receiver for synchronous CCI, but in the asynchronous channel, CCI whitening can be used to improve receiver performance. The SINR-maximizing filter (SINRMF) in an asynchronous channel is derived and shown to be composed of a WMF followed by a discrete time filter. The SINRs of the WMF and SINRMF receivers are analytically evaluated for a standard raised-cosine (RC) and a Beaulieu-Tan-Damen pulse. It is shown that for the RC pulse, the WMF can achieve a SINR gain as large as 1.76 dB over the CMF receiver provided that the transmission is free of intersymbol interference (ISI). The SINR of the ISI-impaired system is also evaluated and the conditions under which this system can achieve close to ISI-free SINR are studied. The SINR is evaluated for the SINRMF and it is shown that this filter can restore much of the SINR loss incurred due to ISI introduced by the WMF.

Kalman filter‐based channel estimation and ICI suppression for high‐mobility OFDM systems

AbstractThe use of orthogonal frequency division multiplexing (OFDM) in frequency‐selective fading environments has been well explored. However, OFDM is more prone to time‐selective fading compared with single‐carrier systems. Rapid time variations destroy the subcarrier orthogonality and introduce inter‐carrier interference (ICI). Besides this, obtaining reliable channel estimates for receiver equalization is a non‐trivial task in rapidly fading systems. Our work addresses the problem of channel estimation and ICI suppression by viewing the system as a state‐space model. The Kalman filter is employed to estimate the channel; this is followed by a time‐domain ICI mitigation filter that maximizes the signal‐to‐interference plus noise ratio (SINR) at the receiver. This method is seen to provide good estimation performance apart from significant SINR gain with low training overhead. Suitable bounds on the performance of the system are described; bit error rate (BER) performance over a time‐invariant Rayleigh fading channel serves as the lower bound, whereas BER performance over a doubly selective system with ICI as the dominant impairment provides the upper bound. Copyright © 2008 John Wiley &amp; Sons, Ltd.

Interference cancellation for OFDM systems in presence of overlapped narrow band transmission system

Narrowband interference (NBI) is one of the most important problems in an OFDM system, which not only degrades the signal performance on the overlapped subcarriers, but also affects the signal performance on the nearby subchannels due to the spectral leakage effect of DFT demodulation at the receiver. In this paper, we consider the NBI problem caused by narrow band digital communication systems, and propose a novel NBI cancellation method. We consider the NBI reconstruction problem including NBI central frequency and its bandwidth estimation. Simulation results show that this method can achieve about 6 dB signal to interference plus noise ratio (SINR) gain if the interference bandwidth is about twice of that OFDM bins and the system SINR is about 0 dB. As the bandwidth of NBI decreases, more SINR gain will be obtained. Meanwhile, we also consider the system implementation problem, it has shown that its implementation complexity is not high based on the current digital signal processing techniques. If zoom FFT is employed in our system, the calculation complexity can he reduced considerably.

On the capture performance of smart antennas in a multicellular environment

In this letter, we present a study of the signal-to-interference-plus-noise ratio (SINR) and throughput efficiency achievable on the uplink of a multicellular environment in the presence of smart antennas at the base station receivers. Both intracell and intercell interferers are explicitly taken into account, as is the SINR gain yielded by optimal beamforming. Different cases are compared, and in particular the tradeoff involved in choosing the frequency reuse plan is considered. It is seen that the system operates most efficiently with full frequency reuse, even though this requires intercell synchronization.